1. Field of the Invention
The present invention relates to an information processing device and method, and an information supply medium, and particularly to an information processing device and method and an information supply medium for detecting commercials contained in a television broadcast.
2. Description of the Related Art
When a recorded television broadcast is reproduced, in order to satisfy users"" needs for continuously watching only a program, there has been provided a video recorder (e.g., a video cassette recorder or xe2x80x9cVCRxe2x80x9d) having a so-called commercial cut function which fast feeds a commercial advertisement (hereinafter referred to as a xe2x80x9ccommercialxe2x80x9d or a xe2x80x9cCMxe2x80x9d).
A commercial detection algorithm used in such a video recorder is based on the following characteristics which are unique to commercials or characteristic of a number of commercials. That is, if the following characteristics are confirmed, the portion thus confirmed is detected as a commercial: a quiet section of 0.1 to 2.0 seconds exists at the start and end times of each commercial; a scene change point of an image exists at each quiet section; the duration of each commercial is equal to an integral multiple of 15 seconds; and (for commercials broadcast outside of the United States, e.g., in Japan) the sound multiplex mode changes from a monaural mode for programs to a stereo mode for commercials.
In television broadcast systems of America and Europe, commercials may be detected on the basis of a black frame or blue frame existing between a program and a commercial.
Therefore, according to a conventional commercial detection algorithm, any commercial in which at least one of the above characteristics is not present, such as a Japanese commercial having a monaural sound multiplex mode, cannot be detected.
Further, according to the conventional commercial detection algorithm, if the above characteristics are contained in a part of a program, that portion of the program is erroneously detected as a commercial.
If the characteristics of commercials which have been used in the conventional algorithm were altered or abolished (for example, if the duration of commercials were changed to an integral multiple of 14 seconds or if inserting of the black frame or blue frame were abolished in America or Europe), no commercial would be detected.
Furthermore, according to the detection method of the quiet section in the conventional commercial detection algorithm, the average level of sound over a section is calculated, and if the average level thus calculated is below a predetermined threshold value, the section concerned is detected as a quiet section. Therefore, the detection precision for the quiet section is different between a case of bad reception of a television broadcast (e.g., if the signal to noise ratio (xe2x80x9cS/Nxe2x80x9d) of sound signals is low due to a weak electric field) and a case where the electric field is not weak, so that no commercial can be reliably detected.
The measurement of the time required for a commercial in the conventional commercial detection algorithm is performed by counting the number of frames, while the number of frames per second is set to about 30 frames. However, since an error of several frames often occurs in the actual broadcast, a margin of error is provided to the threshold value to identify the needed time in connection with the error. Accordingly, erroneous detection or non-detection of commercials occurs due to the margin of error.
Further, when a commercial spot of a TV station is broadcast between a commercial and a program for a short time, e.g., for 5 seconds, the spot is something like a commercial from the perspective of viewers. However, the spot is not detected because it does not have the foregoing characteristics of commercials.
It is an object of the invention to provide a method, apparatus and computer program for correctly detecting commercials contained in television broadcasts.
It is a further object of the present invention to reduce or eliminate the need to view commercials when reproducing previously recorded television broadcasts.
It is a feature of the present invention to stop recording of a television broadcast when a commercial is detected.
It is an additional feature of the present invention to instead index commercials when recording a television broadcast in order to permit the high speed fast forwarding through such commercials, yet preserve the ability to view such commercials according to the wishes of a viewer.
It is an advantage of the present invention to reduce the amount of time a viewer must spend in viewing a desired television program.
It is a further advantage of the present invention to reduce the amount of recording media storage space necessary to record a desired television program, by not recording commercials interspersed with the desired television program.
It is yet another advantage of the present invention to allow a viewer to index commercials to permit the viewing of such commercials when desired by the viewer.
According to one aspect of the invention, there is provided an apparatus for processing a television signal which includes: means for receiving a television signal; means for detecting a commercial candidate section in the television signal; means for determining characteristics of the commercial candidate section; and means for judging whether or not the commercial candidate section is a commercial, based on the characteristics detected by the determining means.
According to another aspect of the invention, there is provided an apparatus for processing a television signal which includes: means for receiving a television signal; means for detecting a commercial candidate section in the television signal; means for determining a frequency of scene changes in the commercial candidate section and for increasing a commercial characteristic value if the frequency of scene changes is above a predetermined level; means for determining whether or not the audio signal in the commercial candidate section has a periodicity, for calculating a level of periodicity detected and for increasing a commercial characteristic value if the calculated periodicity is above a predetermined level; means for determining a level of continuity of the periodicity of the audio signal in the commercial candidate section and for increasing a commercial characteristic value if the continuity is above a predetermined level; means for determining a level of repetition of the video signal in the commercial candidate section and for increasing a commercial characteristic value if the repetition is above a predetermined level; means for detecting a telop in the video signal of the commercial candidate section and for increasing a commercial characteristic value if a telop is detected; means for detecting a character in the video signal of the commercial candidate section and for increasing a commercial characteristic value if a character is detected; means for determining the quietness rate of the commercial candidate section and for increasing a commercial characteristic value if the quietness rate is below a predetermined level; and means for judging whether or not the commercial candidate section is a commercial, based on the commercial characteristic value resulting from the operations of the frequency determining means, the periodicity determining means, the continuity determining means, the repetition determining means, the telop determining means, the character determining means and the quietness rate determining means.
According to another aspect of the invention, there is provided an apparatus for processing a television signal which includes: means for receiving the television signal; means for determining a quiet threshold value from the television signal; means for making a comparison of the audio signal and the quiet threshold value; and means for judging whether or not a portion of the television signal is a commercial candidate section according to the comparison.
According to another aspect of the invention, there is provided an apparatus for processing a television signal which includes: a receiver for receiving a television signal; a first detector for detecting a commercial candidate section in the television signal; a second detector for detecting characteristics of the commercial candidate section; and a judgment circuit for judging whether or not the commercial candidate section is a commercial, based on the characteristics detected by the second detector.
According to another aspect of the invention, there is provided an apparatus for processing a television signal which includes: a receiver for receiving a television signal; a commercial candidate section detecting circuit for detecting a commercial candidate section in the television signal; a commercial characteristic value counter for storing a previous commercial characteristic value, for receiving a commercial characteristic value signal and for adding a commercial characteristic value from the commercial characteristic value signal to the previous commercial characteristic value; a frequency determining circuit for determining a frequency of scene changes in the commercial candidate section and for sending a commercial characteristic value signal to the commercial characteristic value counter if the frequency of scene changes is above a predetermined level; a periodicity determining circuit for detecting whether or not the audio signal in the commercial candidate section has a periodicity, for calculating a level of periodicity detected and for sending a commercial characteristic value signal to the commercial characteristic value counter if the calculated periodicity is above a predetermined level; a continuity determining circuit for determining a level of continuity of the periodicity of the audio signal in the commercial candidate section and for sending a commercial characteristic value signal to the commercial characteristic value counter if the continuity is above a predetermined level; a repetition determining circuit for determining a level of repetition of the video signal in the commercial candidate section and for sending a commercial characteristic value signal to the commercial characteristic value counter if the repetition is above a predetermined level; a telop detecting circuit for detecting a telop in the video signal of the commercial candidate section and for sending a commercial characteristic value signal to the commercial characteristic value counter if a telop exists; a character detecting circuit for detecting a character in the video signal of the commercial candidate section and for sending a commercial characteristic value signal to the commercial characteristic value counter if a character is detected; a quietness rate determining circuit for determining the quietness rate of the commercial candidate section and for sending a commercial characteristic value signal to the commercial characteristic value counter if the quietness rate is below a predetermined level; and a judgement circuit for judging whether or not the commercial candidate section is a commercial, based on the commercial characteristic value in the commercial characteristic value counter.
According to another aspect of the invention, there is provided an apparatus for processing a television signal which includes: a receiver for receiving the television signal; a quiet threshold value determining circuit for determining a quiet threshold value from the television signal; a comparitor for making a comparison of the audio portion of the television signal and the quiet threshold value; and a judging circuit for judging whether or not a portion of the television signal is a commercial candidate section according to the comparison.
According to another aspect of the invention, there is provided a method for processing a television signal which includes the following steps: receiving a television signal; detecting a commercial candidate section in the television signal; determining characteristics of the commercial candidate section; and judging whether or not the commercial candidate section is a commercial, based on the characteristics detected in the determining step.
According to another aspect of the invention, there is provided a method for processing a television signal which includes the following steps: receiving a television signal; detecting a commercial candidate section in the television signal; determining a frequency of scene changes in the commercial candidate section and increasing a commercial characteristic value if the frequency of scene changes is above a predetermined level; determining a periodicity of the audio signal in the commercial candidate section and increasing a commercial characteristic value if the periodicity is above a predetermined level; determining a continuity of a periodicity of the audio signal in the commercial candidate section and increasing a commercial characteristic value if the continuity is above a predetermined level; detecting a repetition of the video signal in the commercial candidate section and increasing a commercial characteristic value if the repetition is above a predetermined level; searching for a telop in the video signal of the commercial candidate section and increasing a commercial characteristic value if a telop is detected; searching for a character in the video signal of the commercial candidate section and increasing a commercial characteristic value if a characters is detected; determining the quietness rate of the commercial candidate section and increasing a commercial characteristic value if the quietness rate is below a predetermined level; and judging whether or not the commercial candidate section is a commercial, based on the commercial characteristic value after the preceding steps are performed.
According to another aspect of the invention, there is provided a method of processing a television signal which includes the following steps: receiving the television signal; determining a quiet threshold value from the television signal; making a comparison of the audio signal and the quiet threshold value; and judging whether or not a portion of the television signal is a commercial candidate section according to the comparison.
According to another aspect of the invention, there is provided a provision medium for providing a program which is readable by a computer to control an apparatus to execute a detection routine for detecting commercials included in a television broadcast, wherein the detection routine includes the following steps: receiving a television signal; detecting a commercial candidate section in the television signal; detecting characteristics of the commercial candidate section; and judging whether or not the commercial candidate section is a commercial, based on the characteristics detected in the determining step.
According to another aspect of the invention, a provision medium provides a program which is readable by a computer to control an apparatus to execute a detection routine for detecting commercials included in a television broadcast, wherein the detection routine includes the following steps: receiving a television signal; detecting a commercial candidate section in the television signal; determining a frequency of scene changes in the commercial candidate section and increasing a commercial characteristic value if the frequency of scene changes is above a predetermined level; determining a periodicity of the audio signal in the commercial candidate section and increasing a commercial characteristic value if the periodicity is above a predetermined level; determining a continuity of a periodicity of the audio signal in the commercial candidate section and increasing a commercial characteristic value if the continuity is above a predetermined level; detecting a repetition of the video signal in the commercial candidate section and increasing a commercial characteristic value if the repetition is above a predetermined level; searching for a telop in the video signal of the commercial candidate section and increasing a commercial characteristic value if a telop is detected; searching for a character in the video signal of the commercial candidate section and increasing a commercial characteristic value if a characters is detected; determining the quietness rate of the commercial candidate section and increasing a commercial characteristic value if the quietness rate is below a predetermined level; and judging whether or not the commercial candidate section is a commercial, based on the commercial characteristic value after the preceding steps are performed.
According to another aspect of the invention, a provision medium provides a program which is readable by a computer to control an apparatus to execute a detection routine for detecting commercials included in a television broadcast, wherein the detection routine includes the following steps: receiving the television signal; determining a quiet threshold value from the television signal; making a comparison of the audio signal and the quiet threshold value; and judging whether or not a portion of the television signal is a commercial candidate section according to the comparison.